Effect of Exosomes Derived from Microvascular Endothelial Cells on Cerebrovascular Formation and Neurological Injury in Vascular Dementia Model
Objective:To investigate the effects of exosomes derived from microvascular endothelial cells on cerebrovascular formation and nerve injury repair in vascular dementia(VD)model mice.Methods:The exosomes of mouse brain microvascular endothelial cells bEnd.3 were extracted by ultra-high-speed centrifugation method.The morphology of exosomes was observed by transmission electron microscopy(TEM),and the diameter distribution of exosomes was detected by nanoparticle tracking analysis(NTA).The expressions of exosomal marker proteins CD63,TSG101 and Alix were detected by Western Blot.Forty mice were divided into Sham group,Model group,exosome group(b-Exo group)and positive control group(DP group)according to numerical random table method,with 10 mice in each group.Except for sham group,the VD model of the other 3 groups was constructed by bilateral common carotid artery constriction method,b-Exo group was intraperitoneally injected with 100μL b-Exo(100μg/mL),DP group was intraperitoneally injected with Donepezil hydrochloride(1 mg/kg),sham group and model group were intraperitoneally injected with equal volume normal saline,once a day,for 28 days.Morris water maze behavior experiment was used to analyze the learning and memory ability of mice,hematoxylin-eosin(HE)staining was used to observe the histopathological changes of mice's hippocampus,immunofluorescence staining was used to detect the formation of blood vessels in mouse brain tissue,and Western Blot was used to detect the expression level of vascular endothelial growth factor(VEGF)protein in mouse hippocampus.The expression of neuron-specific nucleoprotein(NeuN)in the hippocampus of mice was detected by immunofluorescence staining,and the levels of astroglia-derived protein(S-100β)and neuron-specific enolase(NSE)in serum of mice were detected by enzyme-linked immunosorbent assay(ELISA).Results:The particles isolated from bEnd.3 cells showed a round vesicular shape,and CD63,TSG101 and Alix proteins were highly expressed,indicating that the particles were exosomes,denoted b-Exo.Compared with the sham group,the escape latency of mice in the model group prolonged,the number of passing the target quadrant and the percentage of residence time in the target quadrant were reduced,the number of neurons in hippocampal CA1 region reduced,there was obvious pathological injury,angiogenesis was reduced,the relative expression of VEGF protein down-regulated,and the expression of NeuN reduced.Serum levels of S-100βand NSE increased(P<0.05).Compared with the model group,the escape latency of mice in the b-Exo group and DP group shortened,the number of passing the target quadrant and the percentage of residence time in the target quadrant increased,the damage in hippocampal CA1 region significantly reduced,the number of neuron cells increased,the formation of blood vessels increased,the relative expression of VEGF protein up-regulated,and the expression of NeuN was increased.Serum levels of S-100β and NSE decreased(P<0.05).Conclusion:Exosomes derived from microvascular endothelial cells could significantly promote angiogenesis and repair neurological injury in VD mice,and play some therapeutic role in VD mice.
vascular dementiamicrovascular endothelial cellsexosomesangiogenesisneuroprotectionexperimental study
NETL
NSTL
万方数据
维普
